public class Listener implements UserOfRela{
    private static int count = 0;
    public int id;
    int[] follows = new int[10];
    public Listener(){
        id = count++;
    }
    private int num = 0;
    @Override
    public void follow(int id) {
        follows[num++] = id;
    }

    @Override
    public void introduce() {
        System.out.println("我是Listener" + id);
    }

    @Override
    public String toString() {
        return "Listener{" +
                "id=" + id +
                '}';
    }
}
